Caelo CMS MCP server

Caelo

Open-source CMS for websites run with AI. The AI does the work. Caelo keeps your site in shape.

An AI can build a good-looking website in minutes. Running it is the hard part: the tenth page should match the first, a colleague should be able to change something without breaking the design, a mistake should be easy to take back, and nobody should reach your data through an exposed admin login.

Caelo is built for that second day. You describe what you want, in the chat next to your live site or from your own agent. The AI builds it from your site's own parts. You review it, and you decide what goes live.

Why Caelo

One system instead of loose pages

Everything the AI builds comes from the same parts, so the site stays consistent and maintainable.

• Pages are assembled from layouts, templates and modules, styled by one theme. A page never holds raw HTML of its own.
• Plugins for languages, cookie consent, forms, newsletter, comments, ratings and visitor login ship with Caelo.
• SEO is structured fields (meta, canonical, Open Graph, JSON-LD, sitemap), not hand-written markup. Moving a page creates its redirect.
• Staged builds get a quality check: Lighthouse, plus a structure check that catches the same component pasted as free HTML on several pages instead of being one module. A failed check keeps the site from going live until it is fixed or explicitly accepted.

You decide

The AI works a lot and fast, but never over your head.

• Every change lands in a draft. The AI can stage its finished work for review; Publish live is always a human click.
• Hard-to-undo actions (deploys, users and roles, domains, themes and layouts, plugins, bulk deletes, URL moves) pause for your approval right in the chat.
• Every write is a snapshot. Undo works per chat; whole pages, modules or the site can be reverted.
• The same rules apply whether the work comes from the admin chat, the live-edit overlay or your own agent over MCP.

Separated worlds

Visitors only ever reach finished pages. Where the site is built, nobody gets in without logging in.

• The public site is static HTML, served from object storage behind a CDN or from Caddy. Visitor writes (forms, comments, ratings) go through a separate, rate-limited API gateway that never holds admin credentials.
• On Google Cloud, the admin sits behind Identity-Aware Proxy before Caelo's own login is even reached.
• Two Postgres databases with isolated roles: authoring data and public plugin data never share one. Row-level security is forced on every table.
• Plugins the AI writes run in a Deno sandbox with no file, network or environment access, and get only the permissions the Owner grants for that exact version. Release images are signed and verified on install and on every upgrade.

Getting there, and running it

Shortened. The full README is on GitHub.